Installing a Garden Window

Placed in a sunny spot (ideally facing south), a garden window can provide enough sunlight to grow herbs, sprouts, and flowers. Because the window will add extra sunlight to a room, it's usually a good idea
to choose a model with low-E glass. Some kitchen windows have openable sashes and vents. Most feature water-resistant finishes. Depending on the size of the window and your plants, you may want to have one or two shelves (in addition to the base shelf).

Different windows call for different installation techniques. Most models include a nailing flange or brick molding, requiring that the siding be cut back or removed and reinstalled so it butts against the window or the molding. These pages show installation in an existing window opening, where the siding is kept in place.

Prestart Checklist

Time
Once the opening has been cut, about four hours to install a garden window; more time may be required if you need to modify the trim on the inside.

For a watertight seal install self-stick flashing tape and plastic drain screen. If your window is in a fairly protected situation (such as under an eave) or if you do not receive heavy rainfall, you may skip this step and simply wrap the opening with felt.

Step 1

Remove the existing window's casing and perhaps the stool (inside sill) to measure the rough opening. Order a garden window custom-made to fit your opening or plan to modify your framing to accommodate a standard-size unit.

Most manufacturers require that the rough opening be 1/2 inch wider and taller than the window. If you need to make the opening a bit smaller, add pieces of 2x lumber or strips of plywood as needed. Check again for square and straightness.

Unbox the gardenwindow and inspect it for flaws. Make sure any operable parts work smoothly and seal tightly. Remove shelves, but keep in place any packing that keeps the unit from warping as you install it.

Set the window temporarily in place. Use notched pieces of lumber, set at a slight angle toward the house, to hold the window in place. You may need to tack (partially drive) two nails or screws as well.

From the inside check the window for level, plumb, and square, and tap in shims as needed. Note: If you will be installing a continuous support and thick flashing, as shown in steps 9 -- 11, take the thickness of those materials into account when setting the window.

Remove the window. Tack a 1x4 strip as a guide and set the circular saw blade to cut just through the siding . Cut the lines and finish the cuts using a hammer and chisel. If your window requires it, install a drip cap at the top.

Wrap the opening with roofing felt or building wrap. Seal the rough opening as instructed by the manufacturer. For the system shown the first step is to install self-stick flashing to the sill. You may need to spray the area with spray adhesive first.

Set the window in place, making sure the flange or brickmolding rests firmly against the flashing. From the inside adjust with shims as you did in step 6. Drive screws through the flange. If your window does not have a flange, attach through the jambs.

Apply self-stick flashing pieces as directed. First install the bottom horizontal, then the sides, then the top piece. (This arrangement ensures that any accumulation of moisture will flow down over the joints and not be able to seep in.)

While not always required by manufacturers, two metal or decorative wood brackets are good insurance if you have plenty of plants. Locate framing members (don't just attach to the siding) and drive 3-inch screws.